Objective. To determine the trend of circulating pneumonia pathogens and their levels of antimicrobial resistance (AMR) during the pandemic of new coronavirus infection (NCI) and in the early postpandemic period with terminal episodes. Materials and Methods. The peculiarity of this study is the study material – autopsy specimens (lung tissue) obtained from fatal pneumonia cases. Surveillance was conducted from April 2021 to June 2022 in different phases of the epidemic process of the pandemic with the inclusion of periods of decline and wave rises in incidence (I, II, III periods, a total of 435 samples were studied). Postpandemic IV period was considered from August 2022 to July 2023 – 111 samples were examined. A total of 608 bacterial isolates were isolated during postmortem examination of samples from 546 pneumonia patients. Bacteriological examination was performed by the classical method, identification of pathogens and determination of their sensitivity to germicide was performed using a Vitek 2 Compact 30 bacterial analyzer. Results. During four periods of observation there was a change in the rank position of the leading and other pathogens of pneumonia by the frequency of detection from patients: Klebsiella pneumoniae (42.7; 61.1; 62.9; 40.5%), Acinetobacter baumannii (34.0; 20.4; 12.9; 18.9%), Staphylococcus aureus (9.7; 4.3; 12.9; 20.7%), Escherichia coli (14.6; 1.8; 7.6; 11.7%), Proteus mirabilis (2.9; 0.62; 3.5; 8.1%), Pseudomonas aeruginosa (6.8; 11.1; 6.5; 7.2%), and Stenotrophomonas maltophilia (0.8; 0.6; 1.6; 2.7%). The group Enterobacter aerogenes, Serratia marcescens was isolated in 3.9; 1.9; 4.1; 3.6% of cases. Achromobacter xylosoxidans was detected in periods 2 and 4 (1.2; 0.9%). The proportion of carbapenem-resistant strains (carbR) decreased in the postpandemic period for K. pneumoniae (70.5; 81.8; 76.6; 51.1%) and remained high in all periods of observation for A. baumannii (100; 97.0; 100; 95.2%) and P. aeruginosa (57.1;77.8;72.7;100%). S. aureus was represented mainly by germicide-sensitive variants during all periods of observation. Circulation of E. coli in the postpandemic period was due to BLRS producers (63.8% of cases). All 100% of P. mirabilis strains were resistant to cefepime (IV generation cephalosporin). Thus, during the first year of follow-up in the postpandemic period, there was a decrease in the share of K. pneumoniae in the etiology of fatal pneumonias with simultaneous decrease in the level of carb R-variants against the background of decreased pressure of intensive germicide use. The frequency of isolation of fungi of the genus Candida from autopsy specimens was 8.2%. The species structure was represented by 6 species of fungi: C. albicans – 33.3%, C. glabrata – 28.6%, C. krusei – 14.3%, C. tropicalis – 14.3%, C. lusitaniae – 4.8%, C. kefyr – 4.8%. Antimycotic-resistant strains were detected among the fungi C. glabrata and C. krusei, which is probably the reason for the increased proportion of these species in autopsy specimens. Conclusion. Bacteriological study of autopsy material in fatal pneumonias is a significant direction of microbiological monitoring, which allows obtaining important information about the bacterial flora that accompanies the patient's death, about the change of priority pathogens, the extent of their resistance, and the duration of circulation of resistant forms. Key words: pneumonia, fatal outcome, COVID-19 pandemic, postpandemic period, autopsy specimens, bacterial pathogens, circulation trends

An epidemiological and molecular genetic analysis of norovirus outbreaks in the Amur oblast during 2024 is presented. Etiological agents that caused outbreaks were identified – norovirus genovariants GII.4_Sydney [P16] and GII.7 [P7]. Non-compliance with anti-epidemic measures, violation of sanitary legislation in institutions kitchens, presence of sick kitchen staff at the workplace, untimely notification of the Rospotrebnadzor regional offices about emergence of outbreaks among students as well as late isolation of the infected people facilitated emergence and spread of the infection.

Introduction. Chryseobacterium indologenes bacteria are rarely detected, poorly studied opportunistic bacteria of the nonfermenting gram-negative bacilli group that are characterized by high intrinsic and acquired multidrug resistance and involvement in healthcare associated infections. Aim. To analyze detection rate of C. indologenes strains from various biomaterials obtained from patients with pneumonia, as well as levels of pathogen drug resistance to antimicrobial drugs. Materials and methods. The research included 1740 clinical samples obtained from patients with pneumonia hospitalized in in-patient facilities of the Khabarovsk city during the COVID-19 pandemic. Clinical samples included 1305 respiratory samples (744 sputum samples and 561 nasopharyngeal swabs), 435 samples of autopsy material (lung tissue) obtained from patients with a fatal outcome of the disease. The study was performed via classical bacteriological method. Pathogens were identified with Vitek 2 bacteriological analyzer and Vitek MS mass spectrometer. Sensitivity to antimicrobial drugs was determined by disk-diffusion method and in a bacteriological analyzer. Results. A comparative analysis of detection of the entire nonfermenting gram-negative bacteria (NFGNB) group and C. indologenes from various clinical samples was carried out. Detection rate of NFGNB equaled 17.3%. NFGNB were isolated from autopsy material most often ‒ in 31.7% of cases, less often ‒ from sputum and nasopharyngeal smears (13.8% and 10.7%, respectively). C. indologenes was detected in 0.5% of the cases (8 isolates out of 1740 samples). Isolation of this pathogen was most frequent in nasopharyngeal smears – in 1.1% (6 cases out of 561 samples), least frequent ‒ from sputum, which totaled 0.3% (2 isolates from 744 samples). The detection rate of the pathogen in respiratory samples equaled 0.6% (8 isolates out of 1305 samples). This pathogen was not found in the autopsy material. Carbapenem-resistant variants of C. indologenes were isolated in 75% (6 cases out of 8) of the cases. Conclusion. Further intensifying of diagnostic methods will result in more frequent detection of these unusual pathogens, clinical significance of which needs more justification.

Introduction. Acute respiratory viral and pneumococcal infections, the incidence of which is associated with high economic costs, are one of the most important problems in epidemiology and pulmonology. Preventive vaccination is a tool for managing the incidence of acute respiratory viral infection (ARVI) and pneumococcal infections. The issues of medical and economic efficiency of preventive vaccination are constantly in the field of epidemiological surveillance, and the estimates obtained in this case are a necessary condition for making decisions on the viability of investing in its organization.Aim. Expert assessment and predictive modeling of the potential cost-effectiveness of vaccination with pneumococcal and influenza vaccines in immunocompetent adult patients with different levels of risk of acute and chronic respiratory diseases among the builders of the Amur Gas Processing Plant (GPP).Materials and methods. A complex of studies was carried out using the methods of statistics, epidemiological analysis and monitoring, comparative and economic analysis. Determination of the economic profitability of vaccination was carried out on the basis of methods of comparing “costs” and “benefits”. The surveyed cohort is represented by adults working on the construction of the Amur GPP (Svobodny, Amur Region). The main risk factors and inclusion criteria were the conditions of adverse effects of occupational, social and biological factors on human respiratory health. A set of preventive measures was carried out using methods and means of specific prevention of acute and chronic respiratory diseases: anti-influenza (Ultrix Quadri) and pneumococcal (Prevenar-13) vaccines. Efficacy analysis was carried out for 20-, 40- and 60-year-old patients with 1, 2 and 3 risk factors in accordance with the methods of its medical, social and economic evaluation. A retrospective determination of the cases of diseases (deaths) and economic damage prevented as a result of vaccination was carried out on the basis of the difference in morbidity (mortality) rates for the period preceding vaccination and for the period following vaccination. When constructing a predictive model for evaluating the effectiveness of vaccine prevention of respiratory infections, expert assessments, legal documents and the methodology of individual researchers were used.Results. The predicted incidence of pneumonia among the builders of the Amur GPP, taking into account all risk factors, can be 32.3‰. At the same time, the total volume of prevented predictive incidence of pneumonia in the post-vaccination period only with the use of pneumococcal vaccine can be 26.5‰, reducing the initial incidence rate by 5.5 times. As a result of the calculations and economic assessment, it was found that the total (direct and indirect) economic costs of the state and the plant (economic damage) with the incidence of community-acquired pneumonia in the working-age population (20-60 years) on the territory of this construction site is 112,811 rubles. per person per year. Consequently, the prevented economic damage among the employees and builders of the Amur GPP only as a result of the use of the pneumococcal vaccine “Prevenar-13” is 13,537,411 rubles. In addition, immunoprophylaxis with the use of influenza vaccines can reduce the incidence of influenza, ARVI, pneumonia and chronic forms of respiratory diseases, which corresponds to additional prevented economic damage to the plant in the amount of 103,786,764 rubles. Thus, the predicted total prevented economic damage for this plant as a result of vaccination may amount to 117,324,175 rubles.Conclusion. The results of the studies indicate that the implementation of the Program for the Prevention of Acute Respiratory Diseases by means of influenza and pneumococcal vaccines among the builders of the Amur GPP has a high level of medical and socio-economic efficiency, identified on the basis of its predictive modeling and expert assessments.

Objective: to study the seroprevalence of SARS-CoV-2 antibodies (AB) in children in the 2nd year of the COVID-19 pandemic in Russia. Materials and methods: prospective cohort study. The seroprevalence research was conducted among 3670 children aged 1 to 17 y/o from 26 modelling regions of Russia (that have been participating earlier in the five stages of seromonitoring during 2020-2021). The serological testing was carried out in December, 2021. The work was carried out according to a unified methodology set by the Russian Federal Service for Supervision of Consumer Rights Protection and Human Well-Being with the Pasteur Institute of Epidemiology and Microbiology (Saint Petersburg, Russia). The plasma was obtained from 3 ml of venous blood, in which the level of AB to nucleocapsid (NC), and the SARS-CoV-2 receptor-binding domain (RBD) was determined by immunoferment method using reagents for qualitative and quantitative analysis. Results: the analysis of AB seroprevalence to NC and RBD showed the statistically significant increase in the share of seropositivity to RBD in children of all modelling regions (p<0.05). The most seropositive volunteers contained low levels of AB: 31.3-125.6 BAU/ml NC and 22.6-220 BAU/ml RBD. An increase in the level of AB to NC and RBD was accompanied by a decrease in the percentage of seropositive patients. Evaluating the contribution of children to the level of humoral immunity, convalescents (had been ill shortly before the examination), the “anamnesis” (had been ill at previous stages of seromonitoring) and asymptomatic (had been asymptomatically ill) groups were distinguished. The maximum contribution was made by children with asymptomatic cases of COVID-19 in anamnesis: in 82.3% (95% CI 81.1-83.6), of which 76.9% (95% CI 75.5-78.3) AB detected to RBD. The contribution of children of two other groups to the overall level of humoral immunity was 33 times less. Conclusion: statistically significant predominance of AB to RBD above AB to NC and their main contribution to the level of humoral immunity to SARS-CоV-2 (p<0.001).

The aim: to study the structure and dynamics of population immunity to SARSCoV-2 of the population of the Southern Regions of the Far East (SRFE): Khabarovsk, Primorsky Krai and Amur Region during the COVID-19 epidemic in 2020.Materials and methods. The work was carried out according to the program for assessing population immunity to SARS -CoV-2 of the population of the Russian Federation according to the methodology developed by the Rospotrebnadzor with the participation of the St. Petersburg Pasteur Institute. The study was approved by the ethical committee of the St. Petersburg Pasteur Institute. The selection of participants was carried out by a questionnaire method using cloud technologies. The volunteers were randomized by age by stratification into 7 age groups: 1–17, 18–29, 30–39, 40–49, 50–59, 60–69, 70+ years old. Territorial randomization consisted in limiting the engaging of volunteers – no more than 30 people from one enterprise. After the initial cross-sectional study, a 3-stage seromonitoring was carried out, in which the same volunteers participated. Antibodies to the SARS-CoV-2 nucleocapsid were determined in peripheral blood serum by the enzyme immunoassay using an appropriate set of reagents produced by the State Scientific Center for Medical and Biological Sciences of the Rospotrebnadzor (Obolensk). Statistical analysis was performed using the Excel package. The confidence interval for the proportion was calculated using the A. Wald, J. Wolfowitz method with A. Agresti, B.A. Coull’s correction. The statistical significance of the differences was calculated online using a specialized calculator. The statistical significance of the differences was assessed with a probability of p˂ 0.05, unless otherwise indicated.Results. In a comparative analysis, the highest morbidity was observed in the Khabarovsk Territory, the lowest – in the Primorsky Territory. The level of seroprevalence among the population of the region was 19.6 % (95 % CI: 18.2–21.1) in the Khabarovsk Territory, 19.6 % (95 % CI: 18.1–21.2) in the Primorsky Territory19,6 % and 45,5 % (95 % CI: 43.7–47.3) in the Amur region. The highest seroprevalence was noted among 1–17 years old children, mainly due to the subgroup of 14–17-years-olds. The smallest proportion of seropositive was found among 40–49-year-olds in the Khabarovsk Territory (14.7 %, 95 % CI: 11.2–18.6), 18–28-yearolds in the Primorsky Territory (13.3 %, 95 % CI: 10.0–17.1) and 30–39-year-olds in the Amur Region (36.3 %, 95% CI: 31.7–41.6). No statistically significant dependence of seroprevalence on territorial and occupational factors has been established, with the exception of an increase in the proportion of seropositive medical workers in Primorsky Territory. In the process of 3-stage seromonitoring, a regular increase in the proportion of seropositive people was revealed in all SRFE. The resulting tendency is correctly described by a second-order polynomial. A relationship was revealed between the number of convalescents and persons in contact with them, which made it possible to calculate the base reproductive number (R0) in the range from 1.4 (Primorsky Territory) to 2.4 (Amur Region). Analysis of seroprevalent volunteers showed that the number of asymptomatic individuals varied from 94.1 % (95 % CI: 92.8–95.3) to 98.3 % (95 % CI: 98.8–99.2). This indicates that most of the volunteers had COVID-19 asymptomatically.Conclusions. A comparative study showed the prevalence of seroprevalence in the Amur Region compared with the Khabarovsk and Primorsky Territories. The relationship between the number of convalescents and persons in contact with them was noted. The value of the base R0 is calculated. It has been shown that more than 90 % of seropositive individuals in the COVID-10 SRFE were asymptomatic.

Objective. Detection of additional factors favoring progression of COVID-19 and developing lethal outcomes in hospitalized patients. Materials and methods. Analysis of 98 medical records of lethal cases of patients that underwent hospitalization with diagnosis of COVID-19 associated pneumonia of two in-patient facilities of the Amur oblast and Khabarovsk krai was performed. Two groups were formed: first included medical records of patients hospitalized in severe condition (n = 52) and second group included patients with state of moderate severity (n = 46). Length of hospitalization stay, time from admission to the medical facility to progression of the disease, time from hospitalization to death and bacterial pathogens species composition isolated from lungs tissue autopsy material were analyzed. Statistical assessment of obtained data was performed with StatSoft Statistica 12.0. Results. Majority of patients of 1st and 2nd groups (66.7 ± 6.80% and 69.6 ± 6.78%) were hospitalized on fourth day of the COVID-19 clinical manifestations onset or later. Two thirds of patients hospitalized in severe condition progressed to critical health status on 1st–3rd day of hospitalization. Majority of second group patients (65.2 ± 7.02%) deteriorated from moderate severity to severe health condition on 4th–14th day of hospital stay. Bacteriological assessment analysis of autopsy material revealed that material obtained from first group showed more frequent absence of bacterial flora growth compared with second group both in the Amur oblast (44.4 ± 9.74% и 29.4 ± 11.39%) and in the Khabarovsk krai (в 40.0 ± 10.0% and 27.6 ± 8.45% of cases). Klebsiella pneumoniae (57.7 ± 5.86%) and Candida spp. (18.3 ± 4.59%) were revealed more frequently in the structure of diagnosed pathogens. Substantial proportion of pathogens (81.7 ± 4.59%) were isolated in autopsy material of patients which hospital stay was 4 days and longer. Prolonged hospital stay was associated with more frequent detection of K. pneumoniae and Candida spp. in patients that suffered from COVID-19 pneumonia and eventually died from the disease. With duration of hospitalization of 4 days and longer Acinetobacter baumannii – an extremely virulent pathogen with natural drug resistance was isolated from autopsy material. Conclusion. Factors influencing unfavorable outcomes of COVID-19 include signs of secondary bacterial infection as well as detection of aggressive drug-resistant bacterial microflora that most likely had nosocomial origin due to prolonged hospitalization. Key words: bacterial infection, COVID-19 pandemic, disease progression, fatal outcome, hospitalization

The aim of the study is to summarize the results of a study of seroprevalence of children to SARS-CoV-3, obtained during the implementation of the Rospotrebnadzor program to assess seroprevalence to the NC antigen SARS-CoV-2 of the population of 26 regions of the Russian Federation, conducted during the COVID-19 epidemic in 2020. Research methods: the study of seroprevalence in 26 model territories of the Russian Federation was carried out according to a unified methodology developed by Rospotrebnadzor with the participation of the St. Petersburg Pasteur Institute of Epidemiology and Microbiology. The method provided for the formation of a group of volunteers in a model federative entity, including children aged 1–17 years, in which the presence of antibodies to the SARS-CoV-2 nucleocapsid was determined in venous blood plasma by the enzyme-linked immunosorbent assay (ELISA). The examination of volunteers was carried out in 3 stages: June-August, September-October, December. Results: the study found that in most of the areas surveyed, children had a higher level of seroprevalence than adults. It is shown that high seroprevalence is accompanied by statistically significant decrease in morbidity (p0.05). The analysis of seroprevalence at all three stages revealed at least 3 variants of its dynamics: 1) continuous growth of seroprevalence in parallel with the development of the epidemic process; 2) an episodic change in the periods of increase and decrease in the level of seroprevalence; 3) a continuous decrease in seroprevalence at the level of the epidemic process. Comparative determination of seroconversion levels in three age groups – 1–6, 7–13 and 14–17 years – revealed no statistically significant differences between these age groups have been identified. Conclusion: children aged 1–17 years in most of the surveyed territories of the Russian Federation have a higher seroprevalence to SARS-CoV2 than adults. The increase in seroprevalence in children is accompanied by a decrease in the incidence of COVID-19.

Objective – integral analysis of effectiveness of anti-epidemic measures applied towards employees of the Amur gas processing plant assigned for rotational work under conditions of COVID-19 pandemic.Materials and methods. Sero-epidemiological study included a questionnaire survey of 1461 workers who arrived through the “clean corridor” in the Amur Region, followed by sampling of biological material (blood and respiratory smears). Testing of blood sera for the presence of antibodies to SARS-CoV-2 of two classes (IgM and IgG) was carried out applying enzyme immunoassay. Using PCR, respiratory smears were examined for the presence of the agent RNA in them. Statistical processing of the results obtained was carried out using conventional methodsResults and discussion. The presence of antibodies of the IgG class was revealed in (4.7±0.55) % of cases. In a small cohort (1.7±0.34 %) of practically healthy individuals, asymptomatic infection was detected, confrmed either by a positive PCR result (0.76±0.23 %), or by the detection of IgM antibodies (1.0±0.08 %). On the basis of the study carried out by the Federal Service for Surveillance in the Sphere of Consumer Rights Protection and Human Welfare on August 01, 2020, “Temporary recommendations on the procedure for admitting to work on a rotational basis under the risk of COVID-19 spread in the Amur Region” were approved. These recommendations set out the algorithm for observation of incoming workers and the order for triage of shift workers after testing by ELISA and PCR. The results of the study demonstrate the effectiveness of anti-epidemic measures related to ensuring the procedure for admission to work on a rotational basis under the risks of the spread of COVID-19.

The novel coronavirus (SARS-CoV-2) pandemic, dubbed COVID-19, has become one of the most serious challenges for human populations in the vast majority of countries worldwide. Rapid spreading and increased mortality related to it required new approaches to manage epidemic processes on a global scale. One of such approaches was based on analyzing SARS-CoV-2 seroprevalence associated with COVID-19. Our aim was to summarize the results on assessing seroprevalence to the SARS-CoV-2 nucleocapsid antigen (Nc) in residents from 26 regions of the Russian Federation, carried out during the first wave of the COVID-19 epidemic.Materials and methods. Seroprevalence distribution was examined in 26 model regions of the Russian Federation according to the unified method developed by the Rospotrebnadzor with the participation of the Federal State Institution Saint Petersburg Pasteur Research Institute of Epidemiology and Microbiology. Such approach implied formation of a group of volunteer subjects in model geographic region who were tested by ELISA for anti-Nc serum antibody level in peripheral blood. Analyzed primary data obtained in separate regions were either accepted for publication or released.Results. The current paper finalizes the data obtained in all 26 regions of the Russian Federation. The total SARS-CoV-2 seroprevalence was 19.5 (10.0–25.6)% with the maximum and minimum value found in the Kaliningrad Region and the Republic of Crimea, respectively (50.2% vs. 4.3%). A pattern of age-related seroprevalence distribution indicates insignificant predominance of seroprevalence among subjects of 1–17 years old: 22.1 (13.1–31.8)%. Among COVID-19 convalescents positive for SARS-CoV Nc antibodies it reached 60.0 (40.0–73.3)%. The number of contact persons comprised 6285 subjects or 8.5% of total volunteer cohort, with the level of seroprevalence reaching up to 25.3 (17.95–35.8)%. A direct correlation was revealed between levels of seroprevalence in convalescent and contact volunteers. In addition, the reproductive number for SARS-CoV was calculated comprising 5.8 (4.3–8.5) suggesting that one convalescent subject can infect at least 4 healthy individuals. A high level of asymptomatic forms of COVID-19 among seropositive subjects was confirmed empirically comprising up to 93.6 (87.1–94.9)%.Conclusion. A single cross-sectional study performed during 2020 June–August timeframe allowed to assess pattern of sex- and agerelated COVID-19 seroprevalence for general population in 26 Russian Federation regions. The data obtained may serve as a basis for the longitudinal cohort investigation with serial subject sampling. The timing and duration of study will be determined by dynamics of ongoing COVID-19 epidemic.

Plans of taking the material from patients with SARS or suspected SARS, its preparing for transport and delivery to special laboratories are presented. Expediency of genetic diagnosis of SARS on the base of regional State Surveillance centers is pointed.

Aim. To reveal peculiarities of acute respiratory viral infections (ARVI) incidence among population of the Far Eastern Federal District depending on viral etiology during two epidemic seasons (2017-2018 and 2018-2019). Materials and methods. Method of epidemiological analysis by means of ARVI incidence with weekly epidemic thresholds as utilized. Laboratory diagnosis of respiratory viruses was carried out by applying RT-PCR method and test-kits of the Central Research Institute of Epidemiology. In order to determine relations between ARVI incidence and viral etiological structure of ARVI correlation and regression analysis was performed. Results. Identical epidemical tendencies with differences in ARVI incidence intensity were registered in the evaluated constituent entities of the Russian Far East. Utmost intensity of epidemic process was revealed in the Republic Sakha (Yakutia) and Sakhalin Oblast. In the south regions (Khabarovsk and Primorsky Krai, Amur Oblast) ARVI incidence, occasionally excessing epidemic threshold was lower. Territorial and time irregularity is peculiar for etiology of infections in the Russian Far East. During the epidemic season of 2017-2018 statistically significant prevalence was determined for the influenza virus B in Primorsky and Khabarovsk Krai, influenza virus A(H3N2) ‒ in the Sakhalin Oblast, respiratory syncytial virus ‒ in the Republic Sakha (Yakutia), rhinoviruses were dominant in the Amur Oblast. During the 2018-2019 epidemic season influenza virus A(H1N1)pdm09 was mostly prevalent in most of the constituent entities of the Russian Far East. Compared to the other regions of the Far Eastern Federal District in the Amur Oblast were revealed differences in circulation of respiratory viruses predominantly of non-influenza origin during two observed epidemic seasons. Conclusion. Constant evaluation of ARVI epidemics under the conditions of constantly changing landscape of circulating viruses in a particular region can be useful for determination of strategies and tactics of epidemiological response.

The research presents data on evaluation of immunity levels to tick borne encephalitis virus in unimmunized population of the Amur region during 2011-2017.The highest levels of antibodies were detected in population inhabiting middle and south taiga landscape zones. It should be noted that high antibody levels to tick borne encephalitis virus found in local residents show high frequency of contact with infected carriers as well as possible cases of inapparent form of the infection. The form of affiliation to a certain landscape zone well as the quality of territorial development as has considerable importance on the formation of herd immunity to tick-borne encephalitis virus.

Aim. To analyze current epidemiological and epizootological situation on cystic (hydatidiform) echinococcosis in constituent entities of the Far Eastern Federal District (FEFD) of the Russian Federation. Materials and methods. Data of the administrations of the Federal service for surveillance on consumers rights protection and human wellbeing as well as data of the FBIH «Center of hygiene and epidemiology» located in different constituent territories of the FEFD during 2013-2017 was used. A review of scientific papers concerning the topic of the current article was performed. Results. Mainly sporadic cases of the disease were registered in 7 out of 9 constituent entities of the FEFD during the 2013-2017. The Jewish Autonomous district and Kamchatka region were free of the echinococcosis during the 5-year observation period. Echinococcosis cases were registered annually in the Chukotka Autonomous district, Republic Sakha (Yakutia) and Primorsky region. Herewith, the incidence rates in Chukotka Autonomous district and Republic Sakha (Yakutia) notably exceeded the national average. No fatal outcomes due to cystic echinococcosis in the FEFD were registered. Conclusion. Implementation of immunoepidemiological surveillance of the population of different age groups and professions is recommended on the constituent entities with registered cases of cystic echinococcosis.

The research presents data on evaluation of immunity levels to tick borne encephalitis virus in unimmunized population of the Amur region during 2011-2017.The highest levels of antibodies were detected in population inhabiting middle and south taiga landscape zones. It should be noted that high antibody levels to tick borne encephalitis virus found in local residents show high frequency of contact with infected carriers as well as possible cases of inapparent form of the infection. The form of affiliation to a certain landscape zone well as the quality of territorial development as has considerable importance on the formation of herd immunity to tick-borne encephalitis virus.

Designated data represents epidemiologic investigation of food toxicoinfection breakout among pupils of the Amur region. All children that developed the disease attended school canteen.The investigation indicated that the food was cooked under conditions of wastewater disposal malfunction and repair works. The laboratory tests revealed E. faecalis in patients’ stomach washings and washouts of the inventory and dishes from the food unit as well as in the beetroot salad (supposed cause of the disease). The pathogen (E. faecalis) was most likely transmitted in canteen through transitional transmission factors on food due to wastewater disposal malfunction.